Ultimately though, you (and your walls and picture frames) will feel 20hz in your body far more than hear it with your ears.

3) When you get to 20hz and lower you absolutely need a really good driver and enclosure. My EP500 works in this range (just barely though) where as my 10" Polk sub produces no output. You will need a 12" long throw/high output driver at minimum. Ultimately though this is EP600/800 territory. The large enclosure really helps.

Anyway, I am sure others will chime but these are my thoughts. However to be honest, my knowledge on these topics is quite dated and may not be totally accurate with today's speakers.

Edited by Boltron (05/03/1306:18 AM)

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The above stated is right. Below 20Hz you won't hear anything because the sound waves are so large. You still need relatively a lot of power to push the subwoofer driver down that deep because it will be moving a good amount of air even if our ears can't hear it.

So I would think that being able to "feel" it under 20Hz at a low enough volume level that you aren't getting a good amount of "above 20Hz" LFE could prove to be a challenge. Also keep in mind that many times the LFE seems louder in a next door room than it does inside the room with the sub. This also happens in car audio where the bass may be moderate inside a car, but outside seem louder. I was told that it was due to how *long* the sound waves are and that they are (in laymen's terms) outside of the car at really low frequescies before being able to be heard.

Not sure if that is exactly true or not, but I can say this; My family will be watching a TV show in our living room where we have a fairly inexpensive Sony HTIB. They won't have it very loud at all, and I get still hear the subwoofer through the wall in the bedroom. The lower frequecies are just harder to trap inside a space. Ever go to a movie theater early enough that the previews haven't even started? Many times you can hear the LFE of the auditorium right next door despite their efforts in acoustical treatments and sound deadening in each theater.

To answer the other questions, use a SPL meter like mentioned above, and if sub-20Hz is wanted, then a large driver/enclosure will get you there easier than a smaller one. I've got a SVS sub that has almost a 4 CuFt ported enclosure with a 12" woofer and it touches 20Hz, but doesn't go below it. Some people have modded their's to do it, but really you would be more successful with a 15" woofer.

So, I guess after all of these ramblings I should ask the question: Why are your trying to get sub-audible LFE at low levels? I mean, that is the "feel it" zone and if you still want to "feel it" then you are going to need to leave the levels turned up a bit.

Or use tactile transducers (bass/butt shakers). You feel it then, even with the audible levels turned down. I had bass shakers in my first theater, and they are back for V4 and everyone loves them. Mine are set to be a little subtle and to augment the subwoofer itself, but they give the "feel" of sub-20Hz even if I turn the speakers and sub down since they are on their own power source and can be turned up/down independantly.

Although, my room is dedicated and fairly isolated - bedroom mentioned earlier where the TV in the room next door is heard even at low levels, and I can barely hear an action movie going in the theater right below - so I don't worry about turning it down much. Keeps the wife happy.

There's also the human hearing element: our ears are less sensitive to low frequencies (and high?) than to midrange frequencies. So for our hearing to perceive the low frequencies at low volumes, they have to be proportionally louder than the midrange frequencies. That was the idea behind the old "loudness" buttons and behind Audyssey's Dynamic EQ.

To answer the why...Since purchasing my M80's we've done a 180. We now listen to way more music than movie watching. I still watch movies (when the stars align) but in general if I'm home (and awake) the stereos on.I've found alot of good online radio stations but I find I can't get the right bass. I know theres more for alot of the songs.I'm pretty sure there has to be a way to get true full range at breakfast volume(65db @ 4meters).

That's funny, I have M80s too and didn't listen to music much with my Denon 4311ci. Then I got the 3ch ADA1000 and nor listen to music a lot

However to you point, there is not much music content below 20hz. I suspect that what your missing is bass in the range of 60-120hz. That is the punch you feel with most modern music. I don't know that online radio stations provide high quality music content to extend well into the low and high ranges. Also, have you performed room equalization?

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I have adjusted the SPL for each speaker but nothing more.I couldn't get the subs SPL to match but they sound better than ever ( thanks to posts on this forum).I have found quite a few online stations with good audio and good bass output. I have really good bass and its not boomy at any volume. That said I'm pretty sure its my system holding up the lower frequencies.My M80's almost cover the audible bass. They hold their own very well.I'm sure I'm missing something.

2 EP 600's provide pretty good LFE at a lower volume... Much more "fill" if you will.. Plays loud enough that you get the effect, without shaking the house.. However, they can also do the latter if one so chooses....

EP600's are out of the question while were in our current home.I'm curious to know if a 15" Axiom driver is in the works.My subs are good, just looking for what would seem to be the missing piece of the sound puzzle.I want to turn down the volume (and I will, ever so slightly) but turn up the lower frequencies heard.Time to look into room treatments and or better subs.

First point, LFE is low frequency effects occasionally present in the .1 channel in movies. Music has no LFE. With the notable exception of pipe organ music there's almost no bass content below about 40Hz.

Bass frequencies require no more power for a given level than any other; e.g., 20Hz, 200Hz and 2000Hz at 80dB use the same power. What is different is that deep bass frequencies are less audible to humans than are higher frequencies at the same dB level. If you want to make them more audible(or at least equally audible)in relation to the rest of the music, the simplest move is to turn up the bass tone control. There are also built-in or separate parametric equalizers to try to do this a bit more precisely. This boosted audibility of the lowest bass isn't "natural", of course.

So no, your system isn't "holding up the lower frequencies" and you aren't "missing something" that you're supposed to hear.